Cooling fin assembly

ABSTRACT

A cooling fin assembly includes a plurality of fins, each having a latching element on the top edge and the bottom edge, to couple with each other in series, forming an annular arrangement. The fins coupled in the annular fashion are surrounded and confined by a strapping ring. The fins have respectively a bottom plate extended vertically from the fins to be in contact with the top surface of a base, which has a bottom surface in contact with the surface of a heat source, to dissipate heat.

FIELD OF THE INVENTION

The present invention relates to a cooling apparatus for electronicdevices and particularly to a cooling fin assembly, which has finscoupled in series and is arranged in an annular fashion.

BACKGROUND OF THE INVENTION

As the operation clock frequencies of central processing units (CPUs)become faster, the performance of computers also increasessignificantly. More electric power is consumed and more heat isgenerated. The peripheral devices such as hard disk drives, compact diskdrives, graphic chips and system core logic chipsets also generate moreheat as the performances are enhanced. Hence an enhanced cooling devicehas to be provided to transfer the heat energy of the computer to thesurrounding environment, to prevent the computers from being overheatedand malfunctioned.

The CPU is the brain of a computer. As it is in an operating conditionconstantly and processes at a high clock frequency, the CPU generates alot of heat. Heat dissipation is the most important issue. If the CPUcannot be cooled effectively, computer operation could be malfunctioned,and CPU bum out could happen.

The conventional cooling methods now being adopted for the CPU mainlyrely on a combination of fins and fans. Although liquid cooling or heatpipe devices have been developed to enhance heat transfer, the coolingmethods that use liquid as a heat transfer medium are difficult tofabricate and install, and leaking of working fluid is still a problemnot yet fully resolved. Hence a heat sink fin assembly with fins stillhas to be used to cool the working fluid. Therefore the heat sink finassembly is an indispensable cooling device at present.

The heat sink fin assembly has a base, directly in contact with the heatsource, such as the surface of an electronic chip set like CPU totransfer heat to the fins on the base. The heat is carried away by heatconvection. A fan may be added to generate airflow, to form a forcedconvection condition to enhance heat transfer. According to themanufacturing method, the heat sink fin assembly generally can beclassified into two types. One of the two types mostly is made ofaluminum by extrusion, which has a lower thermal resistance, lighterweight, lower cost and may be made easily by extrusion. But the fins,formed by aluminum extrusion have a limited fin pitch and cannotincrease heat transfer area as desired. The other type is to mountcopper fins on an aluminum or copper base, in which the fins can bearranged in a very small pitch to form a heat transfer area to increasecooling efficiency.

To speed up the mounting operation of the fins, many types of serial fincoupling designs have been introduced. These designs couple a pluralityof fins in series through latches. Each fin has a bottom plate bent onone edge. The bottom plates of the fins are coupled and juxtaposed toform a planar area, to be mounted on a base or directly in contact withthe surface of a heat source.

Refer to FIG. 1 for a conventional heat sink 1. The heat sink 1 isformed substantially rectangular, which includes a plurality of fins 2in parallel on a base 3. The fins 2 form an air passage between them. Afan 4 is mounted on the top of the heat sink 1 to generate airflow thatis directed downwards, to the surface of the heat sink 1, and dispelledthrough the front and rear sides of the heat sink 1. The fins 2 on theconventional heat sink 1 have only two sides to channel the airflow, andthe airflow rate is limited. Moreover, the fan 4 directs the airflowdownwards, to directly hit the base of the heat sink 1. The speed of theairflow decelerates greatly and the flow resistance increases. To remedythis problem, R.O.C. patent No. M245505 discloses a heat sink assemblywith the fins arranged in an annular fashion and mounted on a conicalmetal element to increase the airflow passages. But reference No.M245505 does not teach how to arrange the fins in an annular fashion andcouple the fins on the metal element. Arranging the fins rapidly in anannular fashion and mounting on a base still has technical problems inactual implementation. Moreover, while the aforesaid designs whichcouple fins in series provide a serial coupling structure, couplingstructure is located on the top and bottom ends of the fins. The finscoupled in series can only be arranged in a linear fashion and cannot bealtered to mate the base. Hence, how to make arrangement of the finsmore versatile, and form an annular arrangement easily to become acircular fin assembly to be mounted on a heat source or a base securely,are still technical issues remained to be resolved.

SUMMARY OF THE INVENTION

In view of the aforesaid problems, the primary object of the presentinvention is to provide a cooling fin assembly that has fins coupled inseries and forms an annular arrangement so that the entire perimeter ofthe cooling fin assembly becomes airflow channels, thereby reducing theresistance of cooling airflow and increasing cooling efficiency.

In order to achieve the foregoing object, the cooling fin assemblyaccording to the invention includes a plurality of fins coupled inseries and formed in an annular fashion. Each fin has an outer edge, aninner edge, a top edge and a bottom edge. After coupled and formed inthe annular fashion. The top edge and the bottom edge have respectivelya latching element extended outwards in the middle. The latching elementhas a latching section on the end of the latching element and a latchopening on the juncture the latching element and the fin, to be coupledwith the latching section of another fin. The fin, further, has a bottomplate extending vertically from the bottom edge thereof. A strappingring is provided to surround the outer edge of the fins. By means of theconstruction set forth above, the fins that are serially coupled andformed in an annular fashion are distributed radially. Thus airflow canbe channeled in any direction, to reduce flow resistance and increasethe cooling efficiency.

The cooling fin assembly further includes a base, which has a topsurface to be in contact with the bottom plate of the fins. The base hasa bottom surface in contact with the surface of a heat source, totransfer heat to the fins and dissipate the heat by convection.

To anchor a fan securely on the fins, the invention further has aplurality of anchoring elements which have one end fastened to theperipheral edge of the fan and another end latched on the outer edge ofthe fins.

The foregoing, as well as additional objects, features and advantages ofthe invention will be more readily apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a conventional heat sink.

FIG. 2A is a fragmentary schematic view of an embodiment of theinvention showing the radiation fins;

FIG. 2B is a fragmentary enlarged views of FIG. 2A;

FIG. 3 is a fragmentary sectional view of the invention showing the finsand the base;

FIG. 4 is an exploded view of the invention;

FIG. 5 is a side view of the invention;

FIG. 6 is a perspective view of the invention; and

FIG. 7 is a fragmentary sectional view of another embodiment of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 2A and 2B, the cooling fin assembly according to theinvention comprises a plurality of fins 10 coupled in series andarranged in a desired form, such as a linear fashion or an annularfashion.

The fins 10 are made of thermal conductive material such as aluminum orcopper and formed by punching. Each of the fins 10 has an inner edge 11,an outer edge 12, a top edge 13 and a bottom edge 14. After coupled andarranged in an annular shape. The middle portions of the top edge 13 andbottom edge 14 have respectively a latching element 15 extendedvertically towards the same side and is integrally formed on the fin 10by punching. The latching element 15 has a latching section 151 on theend of the fin 10 that has protrusions 151 a on two edges. There is alatching opening 152 formed on a juncture the latching element 15 andthe fin 10 to receive the latch section 151 of another fin 10. The twoprotrusions 151 a have pointed ends spaced from each other at a distancegreater than the width of the latching opening 152, so that the latchingsection 151 can be latched securely in the latching opening 152.Moreover, there is a slot 151 b on the end of the latching section 151to divide the latching section 151 into two parts axially, so that thelatching section 151 has elasticity and may be deformed to change thedistance between the two protrusions 151 a during insertion of thelatching section 151 into the latching opening 152.

The bottom edge 14 abutting the inner edge 11 has a bottom plate 141extended vertically from the fin 10. The bottom plate 141 is fan-shapedby bending a portion of the bottom edge 14 by punching. Therefore, thebottom plate 141 can be coupled by juxtaposing with one another to forman annular or circular planar area, to be in contact with the surface ofa heat source.

Multiple numbers of fins 10 may be coupled in series through thelatching elements 15 on the top edge 13 and the bottom edge 14 to becomea chain, and then be arranged to a desired shape according torequirements. As the fins 10 are coupled in the middle portion of thetop edge 13 and bottom edge 14, the angle between the fins 10 may bechanged as desired without being restricted by the shape and arrangementof the latching element 15. The resulting arrangement of the fins 10 maybe a linear or an annular fashion with a head end coupling with a tailend.

Referring to FIGS. 3 through 6, after the fins 10 are coupled in seriesin a linear fashion, the head end and the tail end may be coupled toform an annular arrangement with the fins 10 positioned radially.

In order to strengthen the coupling of the fins 10, the outer edge 12 ofthe fins 10 has a notch 121 to be coupled by a strapping ring 20, toform a secured fastening to prevent the fins 10 from loosening off. Thestrapping ring 20 is made of a copper band and has a connecting hook 21on one end and a connecting hole 22 on another end to engage with eachother, to confine the fins 10.

The inner edge 11 of the fins 10 forms a holding section 111, to hold acylindrical spacer 30 in the center. The inner edge 11 of the fins 13presses the peripheral surface of the cylindrical spacer 30 withoutjutting in a staggered manner, so that the annular shape may bemaintained intact.

After the fins 10 are coupled in series in the annular fashion, thebottom plates 141 are coupled in a juxtaposed manner to form a circularor an annular plane, to be in contact directly with the surface of aheat source or coupled with a base 40 as shown in FIG. 3. The base 40has a top surface 41 and a bottom surface 42. The bottom plates 141 ofthe fins 10 are in contact with the top surface 41 and bonded bysoldering. The bottom plates 141 may also be coated with a thermalconductive medium and in contact with the top surface 41 while thebottom surface 42 is in contact with the heat source to transfer heat tothe fins 10 for heat dissipation by convection.

To match the packaging type of the electronic chipset, the base 40 hasadopted a two-stage structure. A portion abutting the top surface 41 isa circular plate to mate the circular plane of the coupled bottom plates141 of the fins 10, while the portion adjacent to the bottom surface 42is rectangular to mate the packaging type of the electronic chipset, sothat the base 40 can conduct heat from the electronic chipset throughthe bottom surface 42.

In order to enable the fins 10 and the base 40 to be fixed on theelectronic chipset as desired, the invention further provides a mountingframe 50 and a mounting dock 60.

The mounting plate 50 has a holding bore 51 in the center, mating thebottom surface 42 of the base 40. There is a plurality of apertures 52around the holding bore 51. The base 40 has a plurality of screw holes43 mating the apertures 52, to receive screws (not shown in thedrawings), to fasten the base 40 on the mounting plate 50.

The mounting dock 60 is fixedly mounted onto a circuit board (not shownin the drawings). It has a bottom portion 61 with an open area in thecenter to hold the electronic chipset previously discussed. The mountingdock 60 is coupled with the mounting plate 50 so that the bottom surface42 of the base 40 can be in contact with the electronic chipset, totransfer heat. To couple the mounting plate 50 with the mounting dock60, the mounting plate 50 has a first elastic reed 53 and a secondelastic reed 54 extended outwards from opposite edges. The first elasticreed 53 has a first hooking portion 531 on the end of the first hooksection 531 with an opening directing upwards. The second elastic reed54 has a hooking member 55 which has a second hook section 551 formedwith an L-shape cross section and an opening directing upwards, and ahorizontal bucking section 552. The second elastic reeds 53 and thesecond elastic reeds 54 form an angle with the mounting plate 50, andincline upwards. The mounting dock 60 has a bottom portion 61 with twoside plates 62 extended upwards from opposite edges. Each of the sideplates 62 has a hooking hole 621 corresponding to the first and secondelastic reeds 53, 54 to be coupled with the first hook section 531 andthe hooking member 55 so that the mounting plate 50 may be coupledsecurely on the mounting dock 60. The first and second elastic reeds 53,54 have elasticity to hold the base 40 firmly in contact with thesurface of the electronic chipset.

To couple the mounting plate 50 on the mounting dock 60, first, latchthe first hook section 531 of the first elastic reed 53 in acorresponding hooking hole 621; next, press the bucking section 552 onthe front end of the second elastic reed 54 to latch the second hooksection 551 of the hooking member 55 in another corresponding hookinghole 621; then fasten the mounting plate 50 to the mounting dock 60 toconnect the base 40 with the electronic chipset. To separate themounting plate 50 from the mounting dock 60, remove the base 40 and thefins 10, press the bucking section 552 and move about horizontally tounlatch the second hook section 551 of the hooking member 55 from thehooking hole 621.

The invention further has a plurality of anchoring elements 71 and a fan72. The anchoring elements 71 aim to anchor the fan 72 on the top of thefins 10 to suck in airflow or blow the airflow, to drive the coolingair, to pass over the surface of the fins 10, in order to performcooling. As the fins 10 are arranged in an annular fashion, the entireperiphery of the cooling fin assembly can ventilate air. Compared withthe conventional heat sink that has the fins arranged in parallel withonly two sides to pass the air, the invention has a smaller flowresistance and can increase the amount of the cooling airflow. Inaddition, the outer edge 12 of the fins 10 may be extended outside thebase 40, so that there is a suspended space beneath the bottom edge, 14to further facilitate air circulation.

Each of the anchoring elements 71 has two ends extended axially to forman inserting pillar 711 axially and a flange 712 vertical to the axis.The anchoring element 71 further has a plurality of axial ribs 713 toincrease the strength of the anchoring element 71.

The fan 72 has an annular frame 721 with a plurality of lugs 722extended from the periphery. Each lug 722 has an inserting hole 723 toengage with the inserting pillar 711 of the anchoring element 71 tocouple the anchoring element 71 and the fan 72. The flange 712 of theanchoring element 71 presses the juncture of the outer edge 12 andbottom edge 14 of the fin 10 to anchor the fan 72 on the top edge of thefins 10. If the anchoring element 71 is shorter than the length of theouter edge 12, the outer edge 12 may have an indented portion 122 tolatch with the flange 712, to form a secure anchoring.

Refer to FIG. 7 for another embodiment of the invention. Each of thefins 80 has a bottom plate 841 to form an angle with a bottom edge 84and a latching element 85. When the fins 80 are coupled in series in anannular fashion, the bottom plates 841 are coupled in a conical fashion.The top surface 91 of the base 90 also forms a conical surface matingthe bottom plates 841. Given the same diameter, the conical surfaceprovides a larger contact area than the circular and annular plane, thusthe thermal conductive coefficient of the fins 80 and the base 90increases and the cooling effect of the cooling fin assembly improves.

1. A cooling fin assembly, comprising: a plurality of fins coupled inseries and formed in an annular fashion, each of the fins having anouter edge, an inner edge, a top edge and a bottom edge, the top edgeand the bottom edge having respectively a latching element extendedtowards one side in the middle, the latching element having a latchingsection on the end of the fin and a latching opening on a juncture thelatching element and the fin to receive the latching section of anotherfin to form a coupling condition; a bottom plate extended verticallyfrom the bottom edge thereof; and a strapping ring surrounding theperiphery of the fins.
 2. The cooling fin assembly of claim 1, whereinthe latching section has a protrusion on two edges extending outwards,the two protrusions having respectively a pointed end spaced from eachother at a distance greater than the width of the latching opening. 3.The cooling fin assembly of claim 1, wherein the bottom plate is formedsubstantially in a fan shape and is coupled with one another in ajuxtaposed manner to form an annular plane.
 4. The cooling fin assemblyof claim 1, wherein the bottom plate is formed substantially in a fanshape and is coupled with one another in a juxtaposed manner to form acircular plane.
 5. The cooling fin assembly of claim 1, wherein thestrapping ring is a band which has two ends coupling with each other. 6.The cooling fin assembly of claim 5, wherein the band has two endsformed respectively a connecting hook and a connecting hole.
 7. Thecooling fin assembly of claim 1, wherein the outer edge has a notch tocouple with the strapping ring.
 8. The cooling fin assembly of claim 1further having a base which has a top surface in contact with the bottomplate of the fins and a bottom surface in contact with a heat source. 9.The cooling fin assembly of claim 8, wherein the top surface is conical,the bottom plate of the fins being formed substantially in a fan shapeto form an angle with the latching element such that the bottom plate iscoupled with each other in a juxtaposed manner to form a conicalsurface.
 10. The cooling fin assembly of claim 8, wherein the base is atwo-stage structure which forms a circular plate abutting the topsurface and a rectangular plate abutting the bottom surface.
 11. Thecooling fin assembly of claim 10 further including a mounting frame tolatch on a mounting dock, the mounting frame having a holding boremating the bottom surface of the base.
 12. The cooling fin assembly ofclaim 11, wherein the mounting frame has elastic reeds extended outwardsand upwards in an inclined manner from side edges to form an angle withthe mounting frame, each of the elastic reeds having a front endlatching on the mounting dock.
 13. The cooling fin assembly of claim 12,wherein the mounting dock has a bottom and a plurality of side plates,the bottom having an open area in the center, each of the side plateshaving at least one hooking hole to couple with the front end of theelastic reed.
 14. The cooling fin assembly of claim 12, wherein theelastic reeds includes a plurality of first elastic reeds and aplurality of second elastic reeds, each of the first elastic reedshaving a first hook section on a front end thereof that has a openingdirecting upwards, each of the second elastic reeds having a second hooksection on a front end thereof that has a opening directing upwards anda bucking section.
 15. The cooling fin assembly of claim 12, wherein theelastic reeds includes a plurality of first elastic reeds and aplurality of second elastic reeds, each of the first elastic reedshaving a first hook section on a front end thereof that has a firstopening directing upwards, each of the second elastic reeds having asecond hook section on a front end thereof formed in a L-shaped crosssection that has a opening directing upwards and a bucking section. 16.The cooling fin assembly of claim 1 further having a fan mounted on thefins.
 17. The cooling fin assembly of claim 16 further having aplurality of anchoring elements which have one end coupling with the fanand other end latching on the outer edge of the fins.
 18. The coolingfin assembly of claim 17, wherein each of the anchoring elements has ainserting pillar, the fan having a plurality of inserting holescorresponding to the inserting pillar.
 19. The cooling fin assembly ofclaim 18, wherein the fan has a plurality of lugs on the periphery andthe inserting holes are located on the lugs.
 20. The cooling finassembly of claim 17, wherein each of the anchoring elements has aflange on one end, each of the fins having an indented portion on theouter edge to couple with the flange.